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US4673740A
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US
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Preparation of substituted 2-phenyl-4H-3,1-benzoxazin-4-ones
Assignee: BASF SE
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Filing: 1986-03-24
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Granted: 1987-06-16
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Expires: 2006-03-24
Abstract
Abstract 2-Phenyl-4H-3,1-benzoxazin-4-ones of the general formula I ##STR1## where R 1 and R 2 are each hydrogen or halogen, R 1 may furthermore be methyl or methoxy and R 2 may furthermore be haloalkyl, haloalkoxy, haloalkylmercapto or haloalkylsulfonyl, each of 1 to 3 carbon atoms, are prepared by reacting an appropriate anthranilic acid with an appropriate benzoyl halide in the presence of a base (acylation) and effecting ring closure by removal of water (cyclization), the process being carried out in a suspending agent which is immiscible with aqueous alkali metal hydroxide solution and in the presence of a phase-transfer catalyst.
Inventors
- 👤 Gerhard Hamprecht
- 👤 Wolfgang Rohr
- 👤 Juergen Varwig
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 05:07
CPC Classifications
C; C07; C07D; C07D265/00; C07D265/04; C07D265/12; C07D265/14; C07D265/20; C07D265/22
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
167 words
In a process for the preparation of a 2-phenyl-4-H-3,1-benzozazin-4-one of the formula I ##STR4## where R 1 is hydrogen, halogen, methyl or methoxy and R 2 is hydrogen, halogen or haloalkyl, haloalkoxy, haloalkylmercapto or haloalkylsulfonyl, each of 1 to 3 carbon atoms, by acylation of an antranilic acid II ##STR5## with a benzoyl halide III ##STR6## where Hal is halogen, in the presence of a base and effecting ring closure of the benzoyl anthranilate thus obtained by elimination of water, the improvement in the acylation step which comprises reacting the benzoyl halide III with (a) a mixture of a stoichiometric amount of an at least 25% strength aqueous alkali metal hydroxide solution and a suspension of the anthranilic acid II in a suspending agent which is immiscible with the aqueous alkali metal hydroxide solution or (b) a suspension of an alkali metal salt of anthranilic acid II in a suspending agent as defined under (a) in the presence of a catlytically effective amount of a phase-transfer catalyst.
Claim 2
Dependent Claim
167 words
In a process for the preparation of a 2-phenyl-4-H-3,1-benzozazin-4-one of the formula I ##STR4## where R 1 is hydrogen, halogen, methyl or methoxy and R 2 is hydrogen, halogen or haloalkyl, haloalkoxy, haloalkylmercapto or haloalkylsulfonyl, each of 1 to 3 carbon atoms, by acylation of an antranilic acid II ##STR5## with a benzoyl halide III ##STR6## where Hal is halogen, in the presence of a base and effecting ring closure of the benzoyl anthranilate thus obtained by elimination of water, the improvement in the acylation step which comprises reacting the benzoyl halide III with (a) a mixture of a stoichiometric amount of an at least 25% strength aqueous alkali metal hydroxide solution and a suspension of the anthranilic acid II in a suspending agent which is immiscible with the aqueous alkali metal hydroxide solution or (b) a suspension of an alkali metal salt of anthranilic acid II in a suspending agent as defined under (a) in the presence of a catlytically effective amount of a phase-transfer catalyst.
Claim 3
Dependent Claim
18 words
The process as of claim 1, wherein the acylation is carried out at from 10° to 50° C.
Claim 4
Dependent Claim
45 words
The process of claim 1, wherein the anthranilic acid II is selected from the group consisting of 6-chloro-, 6-fluoro- and 6-bromo anthranilic acid, 6-methyl- and 6-methoxyanthranilic acid. 5-fluoro-, 5-bromo, 5-methyl and 5-methoxyanthranilic acid, 4-fluoro-,4-chloro-, 4-bromo-4-methyl- and 4-methoxyanthranilic acid and 3-fluoro-, 3-chloro-, 3-bromo-3-methyl- and 3-methoxyanthranilic acid.
Claim 5
Dependent Claim
15 words
The process of claim 3, wherein the benzoyl halide is benzoyl chloride of benzoyl bromide.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-06-15 | 1990-12-15 | 1991-06-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-06-15 | 1994-12-15 | 1995-06-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-06-15 | 1998-12-15 | 1999-06-16 | $7700.00 | Window Closed / Lapsed |